Spark-plug for internal-combustion engines.



E. w. COLE.

SPARK PLUG FOR INTERNAL COMBUSTION ENGINES..

APPLICATION FILED Ill-10.8. 1916.

1,257,581. Patented Feb.26,1918.

INVENTOR.

WITNESS Q X f 77 6 77 y fi pg f,

4)! ATTORNEY UNITED STATES PATENT OFFICE.

EARL WESLEY COLE, 0F OVID, MICHIGAN.

SPARK-PLUG FOR INTERNAL-CUMBUSTION ENGINES.

Application filed December 8, 1916.

To all whom it may concern Be it known that I, EARL \VnsLnY Conn, a citizen of the United States, and a resident of Ovid, county of Clinton, and State of Michigan, have invented certain new and useful Improvements in Spar t-?lugs for Internal-Combustion Engines, of which the following is declared to be a full, clear, and exact description.

This invention relates to spark plugs for internal Combustion engines, and its object is to provide means for preventing the accumulation of carbon and other foreign matter upon the porcelain core and adjacent inner wall of the main body of the plug. Another important object is to provide a selfcleaning spark plug. With these and other objects in view, this invention consists in the several novel features hereinafter fully described, and more particularly set forth in the claims.

This invention is clearly illustrated in the drawing accompanying the specification, in which Figure l, is a view partly in side elevation and partly in central. longitudinal section embodying a simple form of the present invention, and Fig. 2, is a cross section taken on the line 2.2 of Fig. 1. These views are upon a somewhat enlarged scale.

Referring to said drawing which illustrates a simple embodimentof the present invention, 3, designates the body of the spark plug of the common and well known construction, having a centrally extending cavity formed therein for receiving a core, 4, usually constructed of porcelain or other nonconducting material secured in said body, 3, by a screw threaded bushing, 5. In accordance with the common practice, the core, 4, is provided with an enlarged portion, 6, arranged for seating upon a shoulder, 7, formed upon the inner wall of the body, 3, and usually washers, 8, 9, are provided on the top and bottom of said enlarged portion, 6. It is understood that the screw threaded bushing bears against the upper side of the washer, 8, and presses the washer, 9, tightly against the shoulder or seat, 7. The core, 4:, projects beyond the enlarged portion, 6, as shown at 10, and extends almost to the lower end of the body, 3. Centrally located within said core, 4, is one of the electrodes, 11, which projects beyond the lower end of the part, 10, of the core, and said electrode is connected at its Specification of Letters Patent.

Patented Feb. 26, 1918.

Serial No. 135,?54.

upper end with a screw threaded stud, 12, which is secured to the core and is provided with a nut, 13, for fastening the terminal end 14, of a conductor cord thereto. At the lower end of the body 3, is a second electrode, 15, which is secured to said body in any suitable manner and projects toward the electrode, 11, a small gap being left between the two electrodes between which the spark is produced. The body portion, 3, is formed with screw threads, 16, whereby it may be screwed into a spark plug opening into the internal combustion engine in accordance with the usual common practice for making a ground with the battery circult or any other source of electric energy. All parts thus far described are old and well known, and I make no claim to them separately from the invention disclosed herein.

In the ordinary spark plug, oil frequently collects upon the portion of the porcelain Core located below the enlarged portion, 6, and carbon frequently is deposited upon said portion of the core, and also upon the internal wall of the body 3, surrounding said portion of the porcelain core. This collection of carbon and oil fouls the plug and prevents the firing thereof, and the parts must be taken apart and the accumulation removed before the spark plug can be of any service.

I have overcome this difiiculty by providmg means around the stem portion, 10, of the core, actuated by the pressure within the cylinder, which means thereby is agitated. and caused to scrape off any accumulations which may lodge upon the stem, 10. and the internal wall of the body surrounding same.

As shown in the accompanying drawing, the said means comprises a washer or ring, 17, surrounding the stem, 10, and normally resting upon the plurality of shoulders, 18, formed upon the internal face of the externally screw threaded portion, 3, said washer or ring practically spans the gap between the stem and adjacent wall of the body, and when moved up and down in said space, contacts with the stem and wall, there-. by scraping oil any accumulations which may lodge thereon, and keeping the surfaces practically clean. The washer is yieldingly held upon its seat by the coiled compression spring, 19, interposed between the washer and the enlargement, 6, of the core, i. Inasmuch as the space above the washer, 17,

in the ordinary and usual spark plug is completely closed to the outer atmosphere, means are provided for permitting outward movement of the air therein during the intervals that the washer is moved toward the enlargement of the core. Said mean comprises an air chamber, 20, formed in the wall of the body, 3, of the plug, and open to the outer atmosphere through a port formed in a screw threaded thimble, 21, which is screwed into the open end of an opening leading the air chamber, 20. Said air chamber communicates with the interior of the plug below the enlargement, (5, through a port, Confined in bllG air chamber, 20, is a valve. 25, here shown in he term of a small ball, which practically fits the bore of the air hamber, 130, and said ball is adapted to seat aga .st a seat, :23, at the lower end of the air chamber, and also against a seat, 4- at the open end of the air chamber. ll hen it seats against the upper seat, 2%, it

closes the port to the outer atmosphere, thereby preventing accidental escape of the compressed explosive mixture, and when seated against the seat, 23, it prevents the entrance of air into the interior of the cylinder.

In the operation of the device, the washer, 17, normally rests upon the shoulders, 18, and the ball valve, rests upon the seat, Upon the strokes of the piston toward thespark plug, the washer, 17, is :t'orced toward the enlarged end, 6, oi the core, the compressed charge being carried up into the chamber within the body of the spark plug, and the ball valve, 25, is thereby forced upward against the seat, 24, thus closing the port to the outer atmosphere. When the pressure in the cylinder is lowered, the spring forces the washer down toward the shoulders, 18, and this movement is aided by the suction caused by the piston in the intake strokes thereof. Upon the reduction of the pressure in the cylinder, the ball valve, 25, is permitted to drop down upon its lower seat, 23, thus closing the port, 22.

In this manner the parts are constantly kept tree from any accumulation of oil or carbon.

More or less variation of the exact details of construction is possible without departing from the spirit of this invention. I desire, therefore, not to limit myself to the xact form of construction as shown and described, but intend in the following claims to point out all of the invention disclosed herein.

1 claim as new and desire to secure by Letters Patent:

1. In a spark plug having a chambered body and a core of non-conducting material, therein, having a part spaced away from the wall of the plug body, a washer suwounding said part or the core, and spanning the annular gap between the body and. core, shoulders on the inner cc of the plug body for limiting movement of the washer in one direction, and a coiled spring surrounding said core and yieldingly holding said washer toward said sl'ioulders. there being a valve controlled air chamber behind said washer.

2. In a spark plug, having a chambered body and a ore out nonconducting material secured therein; a spring pressed cleaning member surrounding said core and spanning the gap between the core and body and movable lengthwise thereof, said body 11H."- inp; valve controlled air chamber cominuni eating; with the chamber of the spark plug behind the cleaning member, and open to the outer atmosphere beyond the valve.

3. A spark plug, comprising a chambered body having an air chamber communicating with the chamber of the body through a port, and having a port opening to the outer atmosphere, a valve movable in said air chamljler, and seat for said valve at both ports, a core or nonconducting material. in said chambered body, a spring pressed washer movable lengthwise of said core a d mpanning the gap between the core and body, and one or more seats -tor said washer:

EARL WESLEY COLE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eaten.

Washington, D, 63. 

